The present invention relates to a connecting blade, which connects two electrical connectors, and an electrical connector having the connecting blade.
Patent Reference has disclosed a conventional connecting blade that connects two electrical connectors. In the conventional connecting blade disclosed in Patent Reference, a plurality of signal line materials made of metal band members is arranged in a width direction of the signal lines, and is held with an insulation board made of an electrically insulating material through an integral molding. The integral molding is performed by injecting an electrically insulating material into a molding die, while maintaining a state that the signal line materials is arranged in the molding die. At this time, the signal line materials receive a pressure during the injection of the electrically insulating material in the molding die. Therefore, it is necessary to restrict movements of the signal line materials in a width direction and/or a sheet thickness direction thereof, so that the signal line materials are not displaced from the normal positions.
In the conventional connecting blade disclosed in Patent Reference, in order to restrict the movements of the signal line materials, a restricting portion may be provided in the molding die. The restricting portion presses both plate surfaces and both side end surfaces of the signal line materials over the whole circumference of the signal line materials at least one position such as a longitudinal direction of the signal line materials. As a result, it is achievable to hold the signal line materials at the normal positions. According to the conventional connecting blade made by such a method, at the positions where the restricting portion of the molding die is provided, the whole circumferences of the signal lines are exposed from the insulation board and contact with air.
Patent Reference: Japanese Patent Application Publication No. 2013-080648
According to the conventional connecting blade disclosed in Patent Reference, the portion where the signal lines are exposed from the insulation board and contact with air, the effective permittivity becomes smaller than that of portions of the signal lines that are covered by the insulation board. As a result, an impedance thereof tends to be higher. In other words, in the conventional connecting blade, there is a difference in the impedance between the portion of the signal lines covered by the insulating material and the portion of the signal lines exposed from the insulating material. For this reason, the impedance tends to vary in the longitudinal direction of the signal lines.
As described above, according to the conventional connecting blade disclosed in Patent Reference, there is the impedance mismatch in the longitudinal direction of the signal lines. As a result, a signal may be deteriorated due to reflection, thereby causing an undesirable effect. Especially, when signals to transmit by the signal lines are high-speed signals, strict impedance matching is required. Therefore, it is necessary to minimize the impedance mismatch.
On the other hand, when the whole circumferential surfaces of the signal lines are covered by the insulation board, in order to match the impedance over the whole range of the signal lines in the longitudinal direction thereof, it is difficult to provide the restricting portion in the molding die to restrict the displacement of the signal line materials. For this reason, it is difficult to maintain the signal lines at the normal positions during the integral molding.
In view of the above problems, an object of the present invention is to provide a connecting blade and an electrical connector having the connecting blade, which can minimize the impedance mismatch of signal lines thereof, while preventing displacement of the signal lines during the integral molding.